Abstract
To identify genes that are differentially expressed by Na+, K+-ATPase inhibitors, we used the differential display technique to compare mRNA expression patterns in rat lens. Lenses were treated with 10 μM ouabain, bufalin, or 19-norbufalin derivative for 24 h and were compared with control lenses. Differential display analysis revealed that one of the down-regulated genes was 14-3-3 θ. Down-regulation was confirmed by Northern blot and by reverse transcription-polymerase chain reaction analysis. Reverse transcription-polymerase chain reaction of additional 14-3-3 isoforms revealed that the η and γ isoforms of 14-3-3 are also down-regulated by ouabain, bufalin, and 19-norbufalin derivative, whereas the zeta isoform is down-regulated only by bufalin. Down-regulation of the 14-3-3 isoforms occurred without a significant change in γ-crystallin gene expression. These results demonstrate that one of the consequences of Na+, K+-ATPase inhibition by exogenous or endogenous inhibitors is the down-regulation of mRNA transcripts encoding several isoforms of 14-3-3. Because the 14-3-3 proteins are multifunctional regulatory proteins, the reduction in the abundance of various isoforms will have profound effects on cell function.
Footnotes
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Send reprint requests to: Dr. David Lichtstein, Department of Physiology, The Hebrew University-Hadassah Medical School, P.O. Box 12272, Jerusalem 91120, Israel. E-mail: david{at}md2.huji.ac.il
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↵1 This study was supported in part by the American National Academy of Sciences through the National Research Council and the Julius Oppenheimer Endowment Fund for Human Health, The Hebrew University, Jerusalem.
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↵2 Present address: Department of Molecular Biology, DuPont Pharmaceuticals, Experimental Station, Wilmington DE 19880-0400.
- Abbreviations:
- DD
- differential display
- RT
- reverse transcriptase
- PCR
- polymerase chain reaction
- Received August 24, 1998.
- Accepted January 20, 1999.
- U.S. Government
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